This invention relates to data recording drives and, more particularly, to a removable cartridge for disk drives that contains a mechanism that restrains the cartridge disk/hub assembly when the cartridge is not in use.
Magnetic disk drives which write and read digital data from flexible magnetic disks are wide spread. xe2x80x9cFloppy disk drivesxe2x80x9d have been extensively used for small, so-called microcomputer systems, for word processing applications and the like. The flexible disk cartridge includes a relatively thin, flexible jacket which is inserted into the floppy disk drive.
Rigid disk drives, such as the Model 3350 produced by IBM Corporation, usually have a fixed rigid magnetic media. The magnetic heads do not contact the magnetic surface, but ride on a thin film of air. Because of this, and other features, these disk drives are capable of extremely precise and high speed operation. This type of disk drive is commonly referred to as a xe2x80x9cWinchesterxe2x80x9d drive.
xe2x80x9cBernoullixe2x80x9d disk drives having performance characteristics similar to that of Winchester drives, but with removable cartridges, have been developed. A flexible magnetic disk is enclosed in a rigid box which is normally completely closed. U.S. Pat. No. 4,400,748 to Bauck et al. and related patents that are assigned to the assignee of the present invention describe drives using Bernoulli flexible disks. U.S. Pat. No. 4,901,173 to Jones et al. Also, related patents that are assigned to the assignee of the present invention describe improvements which relate to so-called xe2x80x9chalf height drives.xe2x80x9d
Rigid disks enclosed in a rigid, removable cartridge, or shell have also been used. U.S. Pat. No. 4,864,452 to Thompson et al. is an example of such a drive.
The JAZ(trademark) drive that is manufactured and sold by the assignee of the present invention, like a Winchester type drive, stores data on rigid recording media.
Removable cartridges that are used with such drives typically have a door which closes the cartridge when it is removed from the drive. The door prevents contamination on the magnetic recording medium when the cartridge is not in the drive. When the cartridge is inserted into the drive, the door slides to an open position to provide access for the magnetic recording heads to engage the recording medium.
When the cartridge is removed from the drive, it is often subject to rough handling. During handling, physical contact of the disk with the shell may damage the disk, particularly if the disk and cartridge shell are subject to excessive xe2x80x9crattlingxe2x80x9d.
U.S. Pat. No. 5,650,899 to Schick (""899xe2x80x9d patent), which is assigned to the assignee of the present invention and incorporated herein by reference in its entirety, shows a non-rattling mechanism for removable cartridges. The cartridge shown in the ""899 patent, which is used with a magnetic disk drive, has a clamping mechanism that is actuated as the door to the cartridge is opened and closed. When the door closes, the mechanism clamps the recording medium against the cartridge shell to prevent the disc from rattling inside the housing, which might otherwise damage the recording disk. When the door opens, the mechanism retracts to free the disk to rotate.
Typically, the door of the ""899 patent cartridge was not self-closing, but rather required a mechanical mechanism within the drive to physically close the door. If the mechanical closing mechanism did not close the door, or if a user opened the door by hand outside of the drive, then the disk is exposed to contaminants.
It is an object of the present invention to provide a device which clamps the disk to the cartridge shell when the cartridge is removed from the drive to prevent rattling of the cartridge, which has sufficient strength to close the cartridge door, and which is easy to assemble.
In accordance with the present invention, a clamping mechanism in a data storage cartridge is actuated when the cartridge is removed from the drive. The mechanism restrains the recording medium to prevent rattling.
The clamping mechanism is driven by the motion of the sliding door. When the door is in a closed position (which corresponds to the cartridge disposed out of the drive) the mechanism expands or extends to restrain the media from rattling inside the cartridge during handling. When the door is in an opened position (which corresponds to the cartridge disposed inside of the drive) the mechanism contracts such that it is free of the hub and the media is free to rotate.
The clamping mechanism includes a rotating cam which rotates in around same axis as the media, a translating cam follower, a door spring, a rotating cam spring, and an arm, which connects the rotating cam to the motion of the sliding cartridge door. The mechanism is mounted on a post in the cartridge top shell half. The clamping mechanism is situated in the cavity formed inside the media hub. The door spring is a torsion spring that is disposed around the post. The door spring has sufficient strength to pivot the door to its fully closed position. The rotating cam spring, which is also disposed around the post, provides torsion to pivot the rotating cam to its clamped state, also referred to herein as its rest state or locked state, that exists while the door is fully closed. The rotating cam has spiral radial lobes that cooperate with spiral slots in the translating member. A rotating cam spring urges the cam actuation.
The mechanism is attached to the sliding door by means of a bent wire which slides in a slot in the end of an arm which pivots about the axis of the recording media. In a preferred embodiment, a member, which is rotatable about the axis of the recording medium, has an arm connected to the door and attaches the sliding door to the mechanism. A wire in an opening in the terminal end of the arm telescopes into and out of the opening as the door travels through its stroke. This provides compliance to account for relative changes in the distance between the mechanism and sliding door attachment point as the door travels through its stroke. A door spring actuates the door via the bent wire.
The mechanism has two states; locked and unlocked, which correspond respectively to the door closed and door opened states. In the locked state, the translating cam follower applies a force against the media hub effectively trapping the hub against the cartridge bottom shell. This force is sufficient to prevent the media from rattling against the cartridge shell halves when out of the drive. In the unlocked state, the translating cam does not contact the hub to allow the media to spin freely when coupled to a spindle motor.
The foregoing and other objects, features and advantages of the invention will be better understood from the following more detailed description and appended claims.